"After a long and controversial discussion with the project admins we've agreed on guidelines for creating a 3rd-party Haiku-based distribution. In brief, other distributions may not use the word 'Haiku' in their name and we will provide a 'Haiku Compatible' logo for distributions that comply to a short list of rules that ensure binary and source compatibility. Please read the detailed guidelines for further information."

It may sound a bit too strict (especially the prohibition on the name), but other than that, I think it stays within the borders of common sense. As I understand, they are talking only about "Haiku distributions" here, and not a modification of the core system (which the Haiku license allows).